class Cake:
    def __init__(self, oven):
        self.oven = oven
    def bake(self):
        return self.oven.turn_on() + ' 蛋糕开始 baking'
    def bake1(self):
        return self.oven.turn_on() + ' 蛋糕开始 baking'




class Oven:
    def turn_on(self):
        return '使用烤箱'

class Microwave:
    def turn_on(self):
        return  '使用微波炉加热'


cake1 = Cake(Oven())
cake2 = Cake(Microwave())

print(cake1.bake())
print(cake2.bake())